Welcome to the Getting Started with GeoStudio video series.
This tutorial guides new users through the basics of creating a simple heat transfer analysis in TEMP/W.
This video will cover how to set up the properties of a TEMP/W analysis in the Definition view,
use the Solve Manager to solve the numerical analysis,
interpret the solved analysis in Results view,
and view and print the analysis in Page Layout mode.
The project definition involves selecting the basic analysis properties,
drawing the model geometry,
creating and assigning material properties,
and defining the boundary and initial conditions.
This tutorial considers transient heat flow through a system comprised of a single material.
Conductive heat flow occurs due to the constant temperature boundary conditions
applied at the ground surface and around the perimeter of a newly installed pipe.
The soil around the pipe exhibits freezing conditions; thus, phase change is present in this analysis.
We will begin on the GeoStudio start page. Here you can create a new project, open an existing project,
or click on the appropriate links to view the examples, tutorial videos,
or engineering books for each GeoStudio product available on the GEOSLOPE website.
When creating a new project, you can select the default units and project page size from a range of standard sizes.
After clicking on the New button, I will select the metric units with the letter-sized page and create an analysis.
Once the new project is created, the Define Analyses window opens where we can edit the analysis tree title,
specify the author, or add comments for future viewers.
We will add a transient TEMP/W analysis to the analysis tree.
We may edit the analysis name,
change the analysis type,
or add a description about the analysis.
In the Physics tab, we can select additional mass or heat transfer processes.
In this case, we will only model heat flow due to conduction, which is the default physical process in TEMP/W.
Next we will look at the Heat tab, which contains the convergence criteria for the analysis.
Here we can change the maximum number of iterations,
the iteration comparison criteria,
or the under-relaxation criteria.
A separate tutorial video is available with a detailed description of the convergence inputs.
More information on these criteria is also provided in the online help.
Under the physical constants, we may also specify the latent heat of water and the phase change temperature.
The Settings tab allows for the selection of the analysis dimensions, which we will leave as two-dimensional.
The Time tab can be used to change the time steps and duration of transient analyses.
For this analysis, let us specify a duration of 730 days with 40 time steps.
We will use the exponential time stepping option, with an initial increment of one day.
Finally, let us save the simulated results every two steps.
We are currently in the Definition view of our analysis.
The red and green lines in the model space represent the x and y axes, respectively,
and the grid is activated.
Both of these may be turned off by going to View | Grid.
The grid spacing and snap to grid option may also be modified here.
Let us change the grid spacing to 0.1 m.
The base units of the analysis are found under View | Units.
Both the base units and the derived units may be modified; however, we will use the default units for this analysis.
The zoom options along the bottom bar of the screen provide various options for adjusting the analysis view.
We can also go to View | Zoom to change the display scale and current zoom percentage,
or zoom to the extents of the modeled domain.
We can add axes to the working area to help visualize the drawing extents of our domain.
Under Sketch Axes, we can modify the titles for each axis and specify the x and y axes extents.
The x axis extents will be -0.2 m to 3 m, and the y axis extents will be -0.2 m to 1.6 m.
You can also modify the axis increments by toggling off the auto increment size button and changing the increment size for each axis.
Given the small size of the modeled domain, let us change the reference scale under Define | Scale to 1:20.
This will ensure that 12-point font is sized correctly when zoomed in at 100%.
Let us now set up the domain geometry.
There are several methods for drawing the model domain.
First of all, we may import regions from DWG or DXF files, or from other GeoStudio files by going to File | Iimport Regions.
We may also import a drawing under Sketch Pictures, scale the drawing to the model domain,
and use it as a reference for creating the desired regions.
Alternatively, we can copy point coordinates from another GeoStudio file
or from spreadsheet software like Microsoft Excel, and paste them into the Define Points window.
Finally, we can draw regions by going to Draw | Regions.
Let us use this last option for defining our embankment geometry.
In the Draw Regions window, ensure the polygonal region type is selected.
Points are automatically generated when we click on the working area and lines are created between these points.
We may also enter point coordinates in the coordinate entry box at the bottom of the window.
To stop the draw regions command, click the right mouse button or press Esc.
We must also add a region representing the pipe. To do so, select the circular floating region in the Draw Regions window.
Click once to define the pipe center and click a second time to set the pipe radius.
In order to adjust these points, let us close the Draw Regions command and go to Define Points.
The last two points represent the pipe center and radius.
We will modify the first point to have the coordinates 1.5 and 1.15,
and the second point to have the coordinates 1.65 and 1.15.
Thus the pipe radius is 15 cm.
Additional points can be added to the domain if required using the Draw Points command.
However, we do not require any other points for this analysis.
The sketch tools in the sketch toolbar may also be used to draw geometric shapes to help us visualize various aspects of our problem.
After defining the model geometry, the next step is to create and assign the material properties.
To establish the material, we will go to Define Materials.
We will click on the Add button to create a new material,
give this material a name, and select the Full Thermal material model from the dropdown menu.
This material model allows for the creation of thermal conductivity and unfrozen volumetric water content functions,
to define the material properties as a soil freezes or thaws.
To add a thermal conductivity function, click on the ellipses button, add a new function,
give it a name,
and select the Spline Data Point Function type.
We can use the internal estimation algorithm to generate the function by clicking the Estimate button.
Select silty-clay from the sample material dropdown menu and enter a frozen thermal conductivity value of 0.0018,
and an unfrozen thermal conductivity of 0.0015 kJ/s/m/°C.
After pressing OK, the function appears in the graph window and the corresponding data points are listed in the data table.
If desired, the Edit Data Points option can be activated and data points within the curve can be deleted,
moved using the left mouse button, or edited manually within the given point list.
Points for the curve can also be added by pasting the points into the data table
provided the appropriate columns are copied from a program such as Microsoft Excel.
The curve properties may be modified using the Curve Fit and Segments scroll bars,
which may be useful if the curve of the function does not pass through the desired data points.
Close this window and select the developed function from the thermal conductivity vs. temperature function dropdown menu.
Now let us add the unfrozen volumetric water content function.
In the function definition window, we will add a new function,
give it a name,
and select the Spline Data Point Function type.
Again we will estimate this function by clicking on the Estimate button.
The estimation method creates a typical unfrozen water content curve based on published literature given the soil type.
As in the thermal conductivity function, we will select the silty-clay from the dropdown menu.
Again we can choose the Edit Data Points option to modify or add data points.
After closing this window, select the developed function from the unfrozen volumetric water content function dropdown menu.
The volumetric heat capacity values are assumed constant for frozen and unfrozen conditions.
Let us enter an unfrozen volumetric heat capacity of 2000 and a frozen volumetric heat capacity of 1900 kJ/m3/°C.
The insitu volumetric water content will be set to 0.38.
Finally, the activation temperature option allows you to choose a specific temperature
for the entire material when it first becomes active in the simulation.
Let us set an activation temperature of 3°C.
The material definition for our analysis is complete so we can close the Define Materials window.
Now we will add the material to our domain by going to Draw Materials, selecting the natural soil material, and clicking on the region.
Creating and assigning boundary conditions is very similar to creating and assigning material properties.
Under Define Boundary Conditions, we will add a new thermal boundary condition to represent the ground surface temperature.
We will set the new boundary condition to a constant temperature of 3°C.
A thermal boundary condition is also required for the pipe so we will add another new boundary condition,
change its name,
and specify a constant temperature of -2°C.
We can change the color of the boundary condition by clicking on the Color: Set button while the item is active.
Now we can open the Draw Boundary Conditions window.
We will apply the ground temperature boundary condition to the surface,
and the pipe temperature boundary condition along the pipe perimeter.
Boundary conditions may also be applied to regions and points depending on the requirements of the analysis.
The last step of developing our numerical analysis is to view the finite element mesh by going to Draw Mesh Properties.
Here we can see that the default mesh is set to have an approximate global element size of 2 m.
We will create a finer discretization for the global mesh by changing this value to 0.05 m.
Mesh constraints can also be applied to individual regions, lines, or points.
If we select the pipe perimeter, we can change the element edge length by selecting the Ratio of Default Size option from the dropdown menu
and changing the value to 0.5.
This creates a finer discretization around the pipe perimeter.
Now we will ensure the analysis is activated in the Solve Manager window and solve the analysis by clicking on the Start button.
Once solved, the window will automatically change to the Results view.
By default, the heat flux vectors appear once the analysis solves.
The Results Times window provides a list of the solved time steps allowing you to view the results for each time step.
We can add contours to the domain by selecting a contour type from the dropdown menu.
We may modify the contour options by clicking on the Draw Contours button.
In this window, we can add a new contour, change the contour increments,
modify the contour color scheme, and add or remove the legend.
Contour labels may be added by selecting Draw Contour Labels and clicking on the desired contour.
The label disappears when we click on the contour a second time.
Visualization of the heat flux vectors is modified in the Draw Vectors window.
Here you can change the vector color, maximum vector length, or the vector magnification.
To add an isoline representing the phase change isotherm, navigate to Draw Isolines.
Here we will add a new temperature isoline at a value of 0°C.
Now when we click through the results times, we can see the change in the extent of the frozen zone surrounding the pipe, over time.
We can choose what items are activated in the Results window at anytime
using the View Preferences toolbar along the right side of the screen.
Here you can toggle on or off results information.
There are other options available for viewing result information.
View Object Information provides information on each geometry item
such as the boundary conditions applied to a line or the mesh properties of a region.
View Result Information provides details for a node, gauss region, and so forth.
This information includes coordinates, temperature, heat flow parameters, material properties, and convergence results,
which can be useful when evaluating or comparing results from specific nodes within the domain.
A report of the analysis may be generated by going to View | Report.
The report is an HTML format file summarizing the input data, domain geometry, and other information from the analysis.
The Draw Graph window offers a wide range of options for plotting the model results.
First, we will check the convergence of our transient analysis by adding a graph and selecting the kind Convergence (each time step).
The convergence parameters are reported with the iteration count vs. time in the graph.
The default maximum number of iterations was set to 50 in our convergence tab.
As indicated by this graph, the maximum iteration count was never reached.
so our transient analysis reached convergence in all time steps.
We can confirm this by changing the second dropdown option to unconverged temperature nodes.
There are no unconverged nodes throughout the analysis so convergence was reached in all time steps.
Now let us create a graph illustrating the cumulative heat rate across the pipe perimeter.
In the graph category dropdowns, we will select heat flow and cumulative energy transfer,
and plot this over all time steps.
Under Set Locations, select the Geometry Items option and click on the pipe perimeter.
Back in the Draw Graph window, select the option Sum (Y) vs. Average (X) Values
so that the graph represents the cumulative energy transfer of all the perimeter nodes summed together.
This linear trend indicates that heat transfer over the pipe perimeter is fairly constant over time,
which corresponds to our system given the constant temperature boundary conditions applied to the pipe and ground surface.
The cumulative energy transfer is negative because heat is leaving the domain.
The More button in the Draw Graph window provides the following options:
to copy the graph as an image so it can be pasted as a picture in another program,
to copy the graph data as tab delimited columns, which can be pasted into other software like Microsoft Excel,
or to export the data to a comma delimited file.
Under Options, we can change the visualization of each plot by customizing the labels, changing the scale of each axis, rotating the graph 90°,
adding or removing the legend, or changing the line style.
If at any time you are unsure about your understanding of a dialogue box,
select the help tab or press F1 on your keyboard to access the Online Help.
If you would like to view the engineering book for the product you are using and do not want to return to the GeoStudio start page,
you can simply click on the Home button in the Online Help.
Once we are finished interpreting the results, we can view the Page Layout layer to set up the printing properties of the project file.
The Page Layout toolbar allows for the selection of the paper size, margins, and orientation,
the portion of the page in which the model appears called the viewport,
and the positioning and size of the model within the viewport.
We may also create, modify, or import a printing template.
A basic template was created when we selected the page size while setting up our project file at the beginning of this tutorial.
That concludes our Getting Started with TEMP/W tutorial video.
Please see the Online Help, supporting documentation for TEMP/W,
and other tutorial videos available on the GEOSLOPE website for more information.
Thank you for watching.